Mounting for loud speakers in pianos



March 19, 1935. J. H. HAMMOND. JR

MOUNTING FOR LOUD SPEAKERS IN PIANOS Original Filed Dec. 18, 1929 2 Sheets-Sheet 1 W 6 I .m l f 0 I L M n (I e 4 It a z i w 2 M i' nu I www 1,, W m. M'

ATTORNEY March 1935- J. H. HAMMOND, JR 1,994,889

MOUNTING FOR LOUD SPEAKERS IN PIANOS Original Filed Dec. 18, 1929 2 Sheets-Sheet 2 Fig. 3

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ATTORNEY Patented Mar. 19, 1935 UNITED- STATES PATENT OFFICE MOUNTING FOR LOUD SPEAKERS IN PIANOS John Hays Hammond, Jr., Gloucester, Mass.

Application December 18, 1929, Serial No. 414,871 Renewed August 31, 1933 9 Claims. (Cl. 179-1) The invention relates in general to pianos, and tions of said sounding board and to produce a more particularly to a piano having a loud speakvarying electric current which is applied to transer associated therewith. formers 15, the secondaries of which are con- The invention further relates to a piano having nected to a plurality of potentiometers 16. Said 3 a radio receiver associated therewith by which potentio'meters are connected in series to a po- 5 radio programs may be received and heard tentiometer 1'1, the movable contact 18 of which through the loud speaker. The piano may also is mounted on a lever 19 which is actuated from include a regenerative arrangement for picking loud pedal 13 by a rod 20. Said rod carries a up the vibrations of the strings and sounding collar 22 which cooperates with lever 19 for elein board, amplifying them by the radio receiver and vating the same when pedal 13 is depressed. delivering the amplified vibrations to the loud Spring 21 may be employed for normally holding speaker, the loud speaker being in regenerative lever 19 in its lower position. relation to the sounding board and strings. Acio receiver 25 which may be of y Well cording to the invention arrangement may be known type as, for example, one including aradio if made for shifting the position of the loud speakfrequency amplifier 26, a detector section 2'7, and 15 er, with respect to the piano sounding board, to an audio frequency amplifier 28 may be condliferent positions for radio reception and piano nected to an antenna 29 through knife switch regenerative operation. 30. The output circuit of receiver 25 may be The invention also consists in certain new and connected to loud speaker 31 by leads 32.

original features of construction and combina- The variable contact 18 and one side of poten- 20 tions of parts hereinafter set forth and claimed. tiometer 17 are connected throu wi ch 23 Although the novel features which are believed across the input circuit of detector section 27 to be characteristic of this invention will be parwhereby the audio frequency currents produced ticularly pointed out in the claims appended by pickup devices 14 y be pp d to Said hereto, the invention itself, as to its objects tectcl' element. amplified in audio amplifier 28 25 and advantages, the mode of its operation and and used to actuate loud speaker 31. the manner of its organization may be better Pickup devices 14 are Preferably located at understood by referring to the following descripantinodal p in 1 s u n rd 12 s that tion taken in connection with the accompanying a maximum response will be obtained. Loud 30 drawings forming a part thereof, in which speaker 31 is preferably located at a nodal point 30 Fig. 1 is a side view of a piano illustrating the on said sounding board so that the operation of invention; the sounding board will not be interfered with Fig. 2 is an end view with a part section taken therebyon the line 22 of Fig. 1; The arrangement for shifting the loud speaker 35 Fig. 3 is an enlarged side elevation with parts 31 Wil n w e d c The Sounding board 35 broken away, further illustrating the shifting 12 is provided with an opening 114 around which arrangement for shifting the loud speaker; and on the lower side is a strip of leather or other Fig. 4 is a bottom plan view of part of the suitable material 115. Located below the openpiano shown in Fig. 3. ing 114 is the loud speaker 31.

I th following description and in the laims Secured to the lower side of the piano is a 40 parts will be identified by specific names for conam 122 v g aligned Openings in Which is venience, but they are intended to be as generic slidably mounted a plunger 121 attached to the in their application to similar parts as the art frame of loud Speaker The P 121 ha will permit. an opening 124 in which is positioned an arm 4 Like reference characters denote like parts in 123 provided with a cam surface 125. The arm 5 the several figures of the drawings. 123 is pivoted to the frame 122 by pivot 140.

Referring to the drawings more in detail, th At the front of the piano is an operating lever invention is shown by way of illustration as ap- 127 having a handle 129 and pivoted to the under plied to a grand piano 10 having strings 11 and surface of the piano by a pivot 128. The arm 12'! a sounding board 12. Loud pedal 13 is employed carries a roller 126 which engages the cam sur- 50 for controlling the amplitude of vibrations of the face 125. It will be seen that by moving the strings in a well known manner. handle 129 back and forth the roller 126 will Located at various points on the sounding move along cam surface 125 and shift the loud board 12 are a plurality of pickup devices 14 speaker 31 from a lower position, as illustrated,

which are adapted to be actuated by the vibrato an upper position with the loud speaker 56 jammed or clamped against the leather washer 115.

To operate the piano as a radio receiver switch 30 is closed and switch 23 is open. The signals received over antenna 29 pass through the radio amplifier 26, detector 27 and audio amplifier 28 to the loud speaker 31. To operate the system as a regenerative piano switch 30 is opened and switch 23 is closed. Vibrations of strings 11 cause vibrations of sounding board 12 which are picked up by pickup devices 14, passed through the audio amplifier 28 and applied to loud speaker 31. The vibrations from loud speaker 31" are impressed on the sounding board 12 and on the strings 11 and are again picked up by the pickup devices 14, amplified by amplifier 28 and again impressed on loud speaker 31, providing a regenerative action. 7

The operation of the piano both as a radio receiver and as a regenerative piano is described in application, Serial No. 384,284, filed August 8, 1929, to which attention is called for a more complete disclosure of the apparatus and the circuits governing the action thereof.

It has been found that a substantial difference in toneis produced by shifting loud speaker 31 from a position against the sounding board 12 to a position spaced therefrom. It has been found that, particularly with a so called dynamic loud speaker, best sound reproduction is obtained when using the system as a regenerative piano, when the loud speaker is moved into a position spaced from the sounding board 12. On the other hand, when the piano is used as a radio receiver best sound reproduction is obtained when the loud speaker 31 is clamped against the sounding board 12.

Although a particular type of loud speaker 31 is disclosed for purposes of illustration, it will be understood that other types of loud speaker may also be used in the present system and in the manner above described. For a more complete draw ing and description of the loud speaker used, for purposes of illustration, attention is called to application, Serial No. 370,484, filed June 13, 1929, now Patent No. 1,893,892, granted Jan. 10, 1933.

Thus, an arrangement has been provided for conveniently changing the relative position of a loud speaker with respect to the sounding board of the piano to obtain different sound reproduction. The loud speaker may be in one position when using the piano as a regenerative piano and it may be in the other position when using the piano as a radio receiver as above described. However, it may be desirable to use both positions of the loud speaker 'to give different effects when both using the piano regeneratively and as a radio receiver.

While certain novel features of the invention have been shown and described and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes in'theforms and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is:

1. The method of operating a piano or the like having a sound board and also having a loud speaker associated therewith which comprises impressing electric variations corresponding to sound variations on said loud speaker and adjusting the distance between the loud speaker as a whole and the sound board to obtain different tone characteristics.

2. In a piano, a piano sounding board having an opening, a loud speaker having a loud speaker frame, a washer of soft material around said opening, an adjustable mounting for said loud speaker whereby said loud speaker frame may be clamped against said washer and may be spaced from said board, selectively.

3. In a piano, a piano sounding board, a loud speaker, a broadcast receiver, means for connecting said sounding board with said receiver and loud speaker to cause the piano to regenerate,-and means for' connecting said receiver and loud speaker to receive a program from sources external to the piano, and means for adjusting the loud speaker with respect to said sounding board to obtain different tone characteristics.

4. In a piano, a piano sounding board, a piano frame supporting said sounding board, a loud speaker having a loud speaker frame, said loud speaker frame having a post attached thereto, said piano frame having a guide slidably seating said post, a member pivoted to said piano frame and to said post. an operating member at the front of the piano and pivoted to the piano frame, one of said members having a cam surface and other member having a follower part engaging said cam surface.

5. In a piano, a piano sounding board, a piano frame supporting said sounding board, a loud speaker having a loud speaker frame, said loud speaker frame having a post attached thereto, said piano frame having a guide slidably seating said post, a rod pivoted to said piano frame and to said post and having a cam surface, an operating lever at the front of the piano pivoted to the piano frame and having a part engaging said cam surface.

6. In a piano, a sounding board, a loud speaker, means for causing said loud speaker to reproduce a broadcast program or the vibrations of said sounding board and means for clamping said loud speaker to said sounding board or spacing it a distance therefrom.

7. In a piano, a vibratable element operated by the keyboard of the piano, a loud speaker, sound amplifying devices, means for placing said vibratable element, said amplifying devices and said loud speaker in sound-transfer relation, and means for adjusting the spacing of said loud speaker with respect to said vibratable element.

8. In a piano, a piano sounding board, a loud speaker, means for impressing electric variations corresponding to sound variations on said loud speaker, and means for adjusting the spacing of the loud speaker as a whole with respect to said sounding board to obtain different tone characteristics.

9. In a musical instrument, a sounding board, a plurality of polyphonic strings adapted to be set into vibration and to impart vibrations to the sounding board, electric pick-up means on said sounding board, a loud speaker adjustably associated with said sounding board, and a power and amplifying device for augmenting the power transmitted to said loud speaker, said amplifying device being fed by said pick-up means, and means for adjusting the spacing of said loud speaker with respect to said sounding board.

JOHN HAYS HAMMOND, JR. 

